In accordance with the present invention, a belt driven power transmission boosting system is described which provides power boost for assisting the driver in steering a vehicle without the energy conversions of current systems. Historically, power delivery has been provided by the engine through a pulley and belt assembly. The present invention also employs that configuration wherein power control utilizes at least two hysteresis clutches to deliver power from the engine. This system is very efficient since the amount of power needed to control the hysteresis clutch is very small compared to the power transferred. Furthermore, the system allows fully variable and controllable quantities of power to be applied to assist the driver in steering the vehicle. The present system requires simple control strategies and provides power to assist in steering the vehicle without the losses of energy conversion inherent in current systems.